imake(1X)																 imake(1X)

NAME

       imake - C preprocessor interface to the make utility

SYNOPSIS

       imake [-Ddefine] [-Idir] [-Ttemplate] [-f filename] [-C filename] [-s filename] [-e] [-v]

OPTIONS

       The  following  command line options may be passed to imake: This option is passed directly to cpp.  It is typically used to set directory-
       specific variables.  For example, the X Window System uses this option to set TOPDIR to the name of the directory containing the top of the
       core distribution and CURDIR to the name of the current directory, relative to the top.	This option is passed directly to cpp.	It is typ-
       ically used to indicate the directory in which the imake template and configuration files may be found.	This option specifies the name	of
       the master template file (which is usually located in the directory specified with -I) used by cpp. The default is Imake.tmpl.  This option
       specifies the name of the per-directory input file.  The default is Imakefile.  This option specifies the name of the  file  that  is  con-
       structed  in  the current directory.  The default is Imakefile.c.  This option specifies the name of the make description file to be gener-
       ated but make should not be invoked. If the filename is a dash (-), the output is written to stdout.  The default is to generate,  but  not
       execute,  a  Makefile.	This  option indicates the imake should execute the generated Makefile.  The default is to leave this to the user.
       This option indicates that imake should print the cpp command line that it is using to generate the Makefile.

DESCRIPTION

       Imake is used to generate Makefiles from a template, a set of cpp macro functions, and a per-directory  input  file  called  an	Imakefile.
       This  allows  machine dependencies (such as compiler options, alternate command names, and special make rules) to be kept separate from the
       descriptions of the various items to be built.

HOW IT WORKS

       Imake invokes cpp with any -I or -D options passed on the command line and passes the name of a file containing the following 3 lines:

       #define IMAKE_TEMPLATE "Imake.tmpl" #define INCLUDE_IMAKEFILE <Imakefile> #include IMAKE_TEMPLATE

       where Imake.tmpl and Imakefile may be overridden by the -T and -f command options, respectively.

       The IMAKE_TEMPLATE typically reads in a file containing machine-dependent parameters (specified as cpp symbols), a site-specific parameters
       file,  a  file defining variables, a file containing cpp macro functions for generating make rules, and finally the Imakefile (specified by
       INCLUDE_IMAKEFILE) in the current directory.  The Imakefile uses the macro functions to indicate what targets should be built; imake  takes
       care of generating the appropriate rules.

       Imake  configuration  files contain two types of variables, imake variables and make variables.	The imake variables are interpreted by cpp
       when imake is run.  By convention they are mixed case.  The make variables are written into the Makefile for later interpretation by  make.
       By convention make variables are upper case.

       The  rules  file  (usually  named Imake.rules in the configuration directory) contains a variety of cpp macro functions that are configured
       according to the current platform.  Imake replaces any occurrences of the string "@@" with a newline to allow  macros  that  generate  more
       than one line of make rules. For example, the macro

       #define program_target(program, objlist)  @@ program:	     objlist	     @@
	       $(CC)  -o  $@  objlist  $(LDFLAGS)

       when called with

       program_target(foo, foo1.o  foo2.o)

       will expand to

       foo:    foo1.o  foo2.o
	       $(CC)  -o  $@  foo1.o  foo2.o  $(LDFLAGS)

       Imake  also  replaces any occurrences of the word "XCOMM" with the character "#" to permit placing comments in the Makefile without causing
       "invalid directive" errors from the preprocessor.

       Some complex imake macros require generated make variables local to each invocation of the macro, often	because  their	value  depends	on
       parameters passed to the macro. Such variables can be created by using an imake variable of the form XVARdefn, where n is a single digit. A
       unique make variable will be substituted.  Later occurrences of the variable XVARusen will be replaced by the variable created by the  cor-
       responding XVARdefn.

       On  systems whose cpp reduces multiple tabs and spaces to a single space, imake attempts to put back any necessary tabs (make is very picky
       about the difference between tabs and spaces).  For this reason, colons (:) in command lines must be preceded by a backslash ().

USE WITH THE X WINDOW SYSTEM

       The X Window System uses imake extensively, for both full builds within the source tree and external software.	As  mentioned  above,  two
       special	variables, TOPDIR and CURDIR, are set to make referencing files using relative path names easier.  For example, the following com-
       mand is generated automatically to build the Makefile in the directory lib/X/ (relative to the top of the sources):

       %  ../.././config/imake	-I../.././config  
	       -DTOPDIR=../../.   -DCURDIR=./lib/X

       When building X programs outside the source tree, a special symbol UseInstalled is defined and TOPDIR and CURDIR are omitted.  If the  con-
       figuration files have been properly installed, the xmkmf script may be used.

INPUT FILES

       Here is a summary of the files read by imake as used by X.  The indentation shows what files include what other files.

	   Imake.tmpl		 generic variables
	       site.def 	 site-specific, BeforeVendorCF defined
	       *.cf		 machine-specific
		   *Lib.rules	 shared library rules
	       site.def 	 site-specific, AfterVendorCF defined
	       Imake.rules	 rules
	       Project.tmpl	 X-specific variables
		   *Lib.tmpl	 shared library variables
	       Imakefile
		   Library.tmpl  library rules
		   Server.tmpl	 server rules
		   Threads.tmpl  multi-threaded rules

       Note  that  site.def  gets included twice, once before the *.cf file and once after.  Although most site customizations should be specified
       after the *.cf file, some, such as the choice of compiler, need to be specified before, because other variable settings may depend on them.

       The first time site.def is included, the variable BeforeVendorCF is defined, and the second time, the variable  AfterVendorCF  is  defined.
       All code in site.def should be inside an #ifdef for one of these symbols.

ENVIRONMENT VARIABLES

       The  following  environment  variables may be set, however their use is not recommended as they introduce dependencies that are not readily
       apparent when imake is run: If defined, this should be a valid include argument for  the  C  preprocessor.   E.g.,  "-I/usr/include/local".
       Actually,  any  valid  cpp  argument  will  work  here.	 If  defined,  this  should  be  a  valid  path  to  a preprocessor program. E.g.,
       "/usr/local/cpp". By default, imake  will  use  /lib/cpp.   If  defined,  this  should  be  a  valid  path  to  a  make	program,  such	as
       "/usr/local/make".  By  default,  imake	will  use  whatever make program is found using execvp(2).  This variable is only used if the "-e"
       option is specified.

FILES

       Temporary input file for cpp Temporary Makefile for -s" Temporary Imakefile if specified Imakefile uses # comments Default C preprocessor

SEE ALSO

       make(1), xmkmf(1X)

       S. I. Feldman, Make -- A Program for Maintaining Computer Programs

AUTHOR

       Todd Brunhoff, Tektronix and MIT Project Athena; Jim Fulton, MIT X Consortium

																	 imake(1X)